Packaging Mechanisms for Dies with Different Sizes of Connectors

ABSTRACT

Embodiments of mechanisms for testing a die package with multiple packaged dies on a package substrate use an interconnect substrate to provide electrical connections between dies and the package substrate and to provide probing structures (or pads). Testing structures, including daisy-chain structures, with metal lines to connect bonding structures connected to signals, power source, and/or grounding structures are connected to probing structures on the interconnect substrate. The testing structures enable determining the quality of bonding and/or functionalities of packaged dies bonded. After electrical testing is completed, the metal lines connecting the probing structures and the bonding structures are severed to allow proper function of devices in the die package. The mechanisms for forming test structures with probing pads on interconnect substrate and severing connecting metal lines after testing could reduce manufacturing cost.

PRIORITY CLAIMS AND CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a divisional application of U.S. application Ser.No. 13/924,215 (Attorney Docket No. TSMC2013-0164), entitled “PackagingMechanisms for Dies with Different Sizes of Connectors” and filed onJun. 21, 2013, which claims the priority of U.S. Provisional ApplicationSer. No. 61/798,136 (Attorney Docket No. TSMC2013-0163P), entitled“Method and Apparatus for a Package Structure,” and filed on Mar. 15,2013, and U.S. Provisional Application Ser. No. 61/791,944 (AttorneyDocket No. TSMC2013-0164P), entitled “Packaging Interconnect StructureApparatus and Method,” and also filed on Mar. 15, 2013. All of theabove-mentioned applications are incorporated herein in their entirety.

BACKGROUND

Semiconductor devices are used in a variety of electronic applications,such as personal computers, cell phones, digital cameras, and otherelectronic equipment, as examples. Semiconductor devices are typicallyfabricated by sequentially depositing insulating or dielectric layers,conductive layers, and semiconductive layers of materials over asemiconductor substrate, and patterning the various material layersusing lithography to form circuit components and elements thereon.

The semiconductor industry continues to improve the integration densityof various electronic components (e.g., transistors, diodes, resistors,capacitors, etc.) by continual reductions in minimum feature size, whichallow more components to be integrated into a given area. These smallerelectronic components also require smaller packages that utilize lessarea and/or lower height than packages of the past, in someapplications.

Thus, new packaging technologies have begun to be developed. By adoptingthe new packaging technologies, the integration levels of the packagesmay be increased. These relatively new types of packaging technologiesfor semiconductors face manufacturing challenges.

BRIEF DESCRIPTION OF THE DRAWINGS

For a more complete understanding of the present disclosure, and theadvantages thereof, reference is now made to the following descriptionstaken in conjunction with the accompanying drawings, in which:

FIG. 1 is a perspective view of a die package, in accordance with someembodiments.

FIG. 2A shows a cross-sectional view of a die package, in accordancewith some embodiments.

FIG. 2B shows a top view of die package of FIG. 2A, in accordance withsome embodiments.

FIGS. 3A-3E illustrate cross-sectional views of a sequential flow offorming an interconnect substrate, in accordance with some embodiments.

FIGS. 4A-4E illustrate cross-sectional views of a sequential flow offorming packaged die, in accordance with some embodiments.

FIGS. 5A-5D illustrate cross-sectional views of a sequential flow offorming die package, in accordance with some embodiments.

FIG. 6 shows a cross-sectional view of a die package, in accordance withsome embodiments.

FIGS. 7A-7E illustrate cross-sectional views of a sequential flow offorming die package, in accordance with some embodiments.

FIG. 8 shows a top view of a die package, in accordance with someembodiments.

FIG. 9A shows a top view of FIG. 5C, in accordance with someembodiments.

FIG. 9B shows a top view of FIG. 5C, in accordance with some otherembodiments.

FIG. 10A shows electrical connections between a number of probing padsand bonding structures of packaged die(s), in accordance with someembodiments.

FIG. 10B shows severed electrical connections between a number ofprobing pads and bonding structures of packaged die(s) after electricaltesting, in accordance with some embodiments.

FIGS. 11A-11C show cross-sectional views of a sequential flow of testingand bonding packaged dies during formation a die package, in accordancewith some embodiments.

Corresponding numerals and symbols in the different figures generallyrefer to corresponding parts unless otherwise indicated. The figures aredrawn to clearly illustrate the relevant aspects of the embodiments andare not necessarily drawn to scale.

DETAILED DESCRIPTION

The making and using of the embodiments of the present disclosure arediscussed in detail below. It should be appreciated, however, that thepresent disclosure provides many applicable inventive concepts that canbe embodied in a wide variety of specific contexts. The specificembodiments discussed are illustrative and do not limit the scope of thedisclosure.

FIG. 1 is a perspective view of a die package 100 including a packageddie 110 bonded to an interconnect substrate 120, which is further bondedto a substrate (or package substrate) 130 in accordance with someembodiments. Two or more packaged dies can be bonded to the interconnectsubstrate 120. The two or more packaged dies could be different from oneanother. However, two or more of the packaged dies bonded to theinterconnect substrate 120 could be identical. For example, twoidentical packaged memory dies and a packaged processing-unit die, suchas central processing unit (CPU) or graphic processing unit (GPU), couldbe bonded to interconnect substrate 120.

Each packaged die, such as packaged die 110 includes at least asemiconductor die (not shown). The semiconductor die includes asemiconductor substrate as employed in a semiconductor integratedcircuit fabrication, and integrated circuits may be formed thereinand/or thereupon. The semiconductor substrate refers to any constructioncomprising semiconductor materials, including, but not limited to, bulksilicon, a semiconductor wafer, a silicon-on-insulator (SOI) substrate,or a silicon germanium substrate. Other semiconductor materialsincluding group III, group IV, and group V elements may also be used.The semiconductor substrate may further comprise a plurality ofisolation features (not shown), such as shallow trench isolation (STI)features or local oxidation of silicon (LOCOS) features. The isolationfeatures may define and isolate the various microelectronic elements.Examples of the various microelectronic elements that may be formed inthe semiconductor substrate include transistors (e.g., metal oxidesemiconductor field effect transistors (MOSFET), complementary metaloxide semiconductor (CMOS) transistors, bipolar junction transistors(BJT), high voltage transistors, high frequency transistors, p-channeland/or n-channel field effect transistors (PFETs/NFETs), etc.);resistors; diodes; capacitors; inductors; fuses; and other suitableelements. Various processes are performed to form the variousmicroelectronic elements including deposition, etching, implantation,photolithography, annealing, and/or other suitable processes. Themicroelectronic elements are interconnected to form the integratedcircuit device, such as a logic device, memory device (e.g., SRAM), RFdevice, input/output (I/O) device, system-on-chip (SoC) device,combinations thereof, and other suitable types of devices.

Interconnect substrate 120 may be made of a semiconductor wafer, or aportion of wafer. In some embodiments, interconnect substrate 120includes silicon, gallium arsenide, silicon on insulator (“SOT”) orother similar materials. Interconnect substrate 120 includesinterconnect structures or redistribution layer(s) (RDL) to electricallyconnect packaged die 110 and substrate 130. RDLs are interconnectstructures near the surface of die packages or on packaging structuresto facilitate electrical connections. In some embodiments, interconnectsubstrate 120 also includes passive devices such as resistors,capacitors, inductors and the like, or active devices such astransistors. In some embodiments, substrate 130 includes additionalintegrated circuits. Interconnect substrate 120 may further includethrough substrate vias (TSVs) and may be an interposer. In addition, theinterconnect substrate 120 may be made of other materials. In someembodiments, interconnect substrate 120 also includes bismaleimidetriazine (BT) resin, FR-4 (a composite material composed of wovenfiberglass cloth with an epoxy resin binder that is flame resistant),ceramic, glass, molding compound, or other supporting materials that maycarry the conductive pads or lands needed to receive conductiveterminals.

Substrate 130 may be made of a semiconductor wafer, or a portion ofwafer. In some embodiments, substrate 130 includes silicon, galliumarsenide, silicon on insulator (“SOI”) or other similar materials. Insome embodiments, substrate 130 also includes passive devices such asresistors, capacitors, inductors and the like, or active devices such astransistors. In some embodiments, substrate 130 includes additionalintegrated circuits. In addition, the substrate 130 may be made of othermaterials. For example, in some embodiments, substrate 130 is amultiple-layer circuit board. In some embodiments, substrate 130 alsoincludes bismaleimide triazine (BT) resin, FR-4 (a composite materialcomposed of woven fiberglass cloth with an epoxy resin binder that isflame resistant), ceramic, glass, plastic, tape, film, or othersupporting materials that may carry the conductive pads or lands neededto receive conductive terminals.

Packaged die 110 is bonded to interconnect substrate 120 via connectors115, and interconnect substrate 120 is bonded to substrate 130 viaconnectors 125. If two or more packaged dies, such as packaged die 110and other packaged die(s), with different sizes of connectors are bondedto interconnect substrate 120, the packaging mechanisms could bechallenging. Further, the cost of manufacturing the die package, such asdie package 100, also needs to be taken into consideration. Interconnectsubstrates 120 with TSVs, which are also called interposers, providefunctions for electrical connection and heat dissipation. However,interposers are expensive. For some applications that require low-costdie packages, alternative die package structures and methods for formingthem are needed.

FIG. 2A shows a cross-sectional view of a die package 100′, inaccordance with some embodiments. Die package 100′ includes a packageddie 110 _(A) and a packaged die 110 _(B). For example, packaged die 110_(A) could be a central processing unit (CPU) or graphic control unit(GPU), and packaged die 110B could be a memory device, such as staticrandom-access memory (SRAM) dynamic random-access memory (DRAM), orother types of memory devices. Packaged die 110 _(B) could have a largenumber of inputs/outputs (I/Os). As a result, the external connectorsfor packaged die 110 _(B) are small bumps, such as micro-bumps(μ-bumps). Packaged die 110 _(A) has connectors with different sizes.FIG. 2A shows packaged die 110 _(A) has large connectors and smallconnectors. The small connectors are about the same size as theconnectors of packaged die 110 _(B). The large connectors of packageddie 110 _(A) are bonded directly to substrate (or package substrate)130′ to form bonding structures 115 _(A). The small connectors ofpackaged die 110 _(A) and packaged die 110 _(B) are bonded to aninterconnect substrate 120′ to form bonding structures 115 _(B). Theinterconnect substrate 120′ is electrically connected to interconnectstructure 135 of substrate 130′ via connectors 125′. FIG. 2A also showsexternal connectors 138′ bonded to substrate 130′.

FIG. 2B shows a top view of die package 100′ of FIG. 2A, in accordancewith some embodiments. FIG. 2B shows that packaged die 110 _(A) isplaced next to packaged die 110 _(B). Interconnect substrate 120′ isdisposed below packaged die 110 _(B) and a portion of packaged die 110_(A). The bonding scheme shown in FIG. 2A does not involve a substratewith TSVs, whose manufacturing cost is high. As a result, the scheme inFIG. 2A saves manufacturing cost. Embodiments of mechanisms for formingdie package 100′ are described below.

FIGS. 3A-3E illustrate cross-sectional views of a sequential flow offorming interconnect substrate 120′, in accordance with someembodiments. FIG. 3A shows a redistribution structure 302 formed over asubstrate 301. As mentioned above, the substrate 301 for interconnectsubstrate 120′ may be made of a semiconductor wafer, glass, or otherapplicable materials. In some embodiments, substrate 301 includessilicon, glass, gallium arsenide, silicon on insulator (“SOT”) or othersimilar materials. FIGS. 3A-3E only show a region 300 of a singleinterconnect substrate 120′. During processing, a number of interconnectsubstrate 120′ are formed on substrate 301. At the end of the processingsequence, substrate 301 is sawed to separate into individualinterconnect substrates 120′. Interconnect substrate 120′ does notcontain active devices, such as transistors, memory devices, etc.However, interconnect substrate 120′ contains passive devices, such asresistors or capacitors, in some embodiments. As a result, themanufacturing cost of interconnect substrate 120′ is relative low andlower than an interposer with TSVs.

FIGS. 3A-3E show region 300 of interconnect substrate 120′, inaccordance with some embodiments. During processing, the substrate 301includes a number of regions similar to region 300 for formingadditional interconnect substrates 120′. The redistribution structure302 includes one or more redistribution layers (RDLs), which areinsulated by passivation layers. Examples of redistribution structuresand bonding structures, and methods of forming them are described inU.S. application Ser. No. 13/427,753, entitled “Bump Structures forMulti-Chip Packaging,” filed on Mar. 22, 2012 (Attorney Docket No.TSMC2011-1339), and U.S. application Ser. No. 13/338,820, entitled“Packaged Semiconductor Device and Method of Packaging the SemiconductorDevice,” filed on Dec. 28, 2011 (Attorney Docket No. TSMC2011-1368).Both above-mentioned applications are incorporated herein by referencein their entireties.

FIG. 3A also shows that corners 303 are formed by removing portions ofsubstrate 301. In some embodiments, corners 303 are removed by laser (alaser-grooving process), which removes trenches in substrate 301. Othermaterial-removal process may also be used. Region 300 includes corners303, which are half of the trenches. FIG. 3A shows that each of corners303 has a slanted sidewall. In some embodiments, the angle, θ, betweenthe slanted sidewall and a normal to the substrate surface is in a rangefrom about 30 degrees to about 60 degrees. Corners 303 can be formedbefore or after the formation of redistribution structure 302. In someembodiments, corners 303 are formed after the formation ofredistribution structure 302.

A plating seed layer 304 is then formed on redistribution structure 302as shown in FIG. 3B in accordance with some embodiments. In someembodiments, the plating seed layer 304 is made of copper and is formedby physical vapor deposition (PVD). However, other conductive film mayalso be used. For example, the plating seed layer 304 may be made of Ti,Ti alloy, Cu, and/or Cu alloy. The Ti alloy and Cu alloy may includesilver, chromium, nickel, tin, gold, tungsten, and combinations thereof.In some embodiments, the thickness of the plating seed layer 304 is in arange from about 0.1 μm to about 0.8 μm. In some embodiments, theplating seed layer 304 includes a diffusion barrier layer, which isformed prior to the deposition of the plating seed layer. The platingseed layer 304 may also act as an adhesion layer to an underlying layer.In some embodiments, the diffusion barrier layer is made of Ti with athickness in a range from about 0.03 μm to about 0.1 μm. However, thediffusion barrier layer may be made of other materials, such as TaN, orother applicable materials and the thickness range is not limited to therange described above. The diffusion barrier layer is formed by PVD insome embodiments.

After plating seed layer 304 is formed, a photoresist layer 305 isdefined over it, as shown in FIG. 3B in accordance with someembodiments. The photoresist layer 305 may be formed by a wet process,such as a spin-on process, or by a dry process, such as by applying adry film over the surface of the plating seed layer 304. After thephotoresist layer 305 is formed, the photoresist layer 305 is patternedto formed openings 306, which are used form connectors (or bondingstructures, such as bumps) for the single interconnect substrate 120′.FIG. 3B also shows that photoresist layer 305 is also removed nearcorners 303 to form exposed regions 306′. The patterning processesinvolved include photolithography and resist development. In someembodiments, the width W₁ of openings 306 is in a range from about 10 μmto about 60 μm. In some embodiments, the depth D₁ of openings 306 is ina range from about 15 μm to about 80 μm.

Afterwards, a conductive layer 307 is plated on the surface of exposedplating seed layer 304, such as over the surfaces in openings 306 andover surfaces of exposed regions 306′, in accordance with someembodiments. The conductive layer 307 is made of copper, copper alloy,or a combination thereof in some embodiments. Following the formation ofthe first conductive layer 307, a solder layer 308 is formed overconductive layer 307. In some embodiments, both the conductive layer 307and solder layer 308 are formed by plating processes. FIG. 3C shows theconductive layer 307 and solder layer 308 after their formation, inaccordance with some embodiments. In some embodiments, the thickness ofconductive layer 307 in openings 306 is in a range from about 10 μm toabout 30 μm. In some embodiments, the thickness of solder layer 308 inopenings 306 is in a range from about 5 μm to about 40 μm.

The thickness of conductive layer 307 and solder layer 308 over exposedregions 306′ are thicker than in openings 306 due to larger exposedsurface area during plating processes. In some embodiments, thethickness of conductive layer 307 over exposed regions 306′ is in arange from about 12 μm to about 40 μm. In some embodiments, thethickness of solder layer 308 over exposed regions 306′ is in a rangefrom about 5 μm to about 40 μm.

After the formation of the conductive layer 307 and solder layer 308,the photoresist layer 305 is removed, as shown in FIG. 3D in accordancewith some embodiments. The removal process may involve dry or wetetching. An etch process is then performed to remove the plating seedlayer 304 not covered by conductive layer 307 and solder layer 308.

After the photoresist layer 305 is removed and the etching of exposedplating seed layer 304, the conductive layer 307 and solder layer 308 inthe openings 306 are exposed to form external connectors (or bumpstructures) 310. The exposed conductive layer 307 and solder layer 308formed over the posed regions 306′ form contact structures 311.

A reflow process is then conducted to reflow the solder layer 308 overthe patterned conductive layer 307 to prepare external connectors 310for bonding. The solder layer 308 covering the conductive layer 307 nearover exposed regions 306′ is also reflowed to cover side wall(s) ofconductive layer 307, as shown in FIG. 3D in accordance with someembodiments.

Following the reflow process described above, substrate 301 is thinneddown to a thickness T₁, as shown in FIG. 3E in some embodiments. Thethinning process may apply a grinding process. In some embodiments,thickness T₁ is in a range from about 20 μm to about 50 μm μm. Followingthe thinning process, region 300 is singulated into individual piecefrom the entire substrate 301 for further packaging, to be describedbelow. The singulation process is a sawing process, in accordance withsome embodiments. In some embodiments, neighboring contact structures311 of neighboring interconnect substrate 120′ are connected to oneanother prior to singulation process and are separated from one anotherafter the singulation process. A portion of each contact structure 311is in the scribe line, which is the region for sawing blade to cutthrough, for such embodiments.

FIGS. 4A-4E illustrate cross-sectional views of a sequential flow offorming packaged die 110 _(A), in accordance with some embodiments. FIG.4A shows a redistribution structure 402 formed over a region 400 ofsubstrate 401, which includes semiconductor devices (not shown),interconnect structures (not shown), and contact pads (not shown), whichare formed over interconnect structures to make electrical connectionswith the semiconductor devices. The semiconductor devices may be activeor passive. The interconnect structures may include metal layers anddifferent layers of vias, which are used to connect metal layers. Theconductive layers of the interconnect structures are insulated bydielectric layers. The redistribution structure 402 is formed overcontact pads to make electrical connection to contact pads andsemiconductor devices in substrate 401. FIGS. 4A-4E only show region 400of a single die. During processing, a number of dies are formed onsubstrate 401. At the end of the processing sequence, substrate 401 issawed to separate into individual packaged die 110 _(A).

The redistribution structure 402 includes one or more redistributionlayers (RDLs), which are insulated by passivation layers. A plating seedlayer 404 is then formed on redistribution structure 402 as shown inFIG. 4B in accordance with some embodiments. Plating seed layer 404 issimilar to plating seed layer 304 described above. In some embodiments,the thickness of the plating seed layer 404 is in a range from about 0.1μm to about 1.0 μm. In some embodiments, the plating seed layer 404includes a diffusion barrier layer, which is formed prior to thedeposition of the plating seed layer. The plating seed layer 304 mayalso act as an adhesion layer to under layer. In some embodiments, thediffusion barrier layer is made of Ti with a thickness in a range fromabout 0.01 μm to about 0.1 μm.

After plating seed layer 404 is formed, a photoresist layer 405 isdeposited and patterned over it, as shown in FIG. 4B in accordance withsome embodiments. The process of forming photoresist layer 405 issimilar to the process of photoresist layer 305. The material used forforming photoresist layer 405 could also be similar to photoresist layer305. Following the patterning of photoresist layer 405, a conductivelayer 407 is plated on the surface of exposed plating seed layer 404,such as over the surfaces in openings (406). The conductive layer 407 ismade of copper, copper alloy, or a combination thereof in someembodiments. In some embodiments, the thickness T₂ of conductive layer407 formed in openings 406 is in a range from about 20 μm to about 80μm. In some embodiments, the width W₂ of conductive layer 407 formed inopenings 406 is in a range from about 60 μm to about 300 μm.

Afterward the conductive layer 407 is formed and the photoresist layer405 is removed, as shown in FIG. 4C in accordance with some embodiments.The removal process may involve dry or wet etching. After thephotoresist layer 405 is removed, the conductive layer 407 in theopenings 406 is exposed. In some embodiments, the thickness T₂ ofconductive layer 407 formed in openings 406 is in a range from about 20μm to about 80 μm. In some embodiments, the width W₂ of conductive layer407 formed in openings 406 is in a range from about 60 μm to about 300μm.

After photoresist layer 405 is removed, a photoresist layer 408 isdeposited and patterned over substrate 401, as shown in FIG. 4D inaccordance with some embodiments. The process of forming photoresistlayer 408 is similar to the process of photoresist layer 405. Thematerial used for forming photoresist layer 408 could also be similar tophotoresist layer 405. The patterns of the photoresist layer 408 includeopenings (409 _(I)) and (409 _(II)). FIG. 4D shows that the sizes ofopenings (409 _(I)) are substantially the same as the sizes ofstructures of conductive layer 407 of FIG. 4C. The sizes of openings(409 _(II)) are smaller than the sizes of openings (409 _(I)) to formsmaller connectors (or bump structures). In some embodiments, the widthW₃ of openings (409 _(II)) is in a range from about 50 μm to about 290μm.

Following the patterning of photoresist layer 408, a conductive layer410 and a solder layer 411 are plated on substrate 401 to fill at leastportions openings (409 _(I)) and (409 _(II)), as shown in FIG. 4D. Theconductive layer 410 is made of copper, copper alloy, or a combinationthereof in some embodiments. The solder layer 411 is formed over theconductive layer 410. Due to difference in sizes of openings (409 _(I))and (409 _(II)), the thicknesses of conductive layer 410 and solderlayer 411 formed in these two types of openings are different. Platingprocess would grow thicker films in wider openings. In some embodiments,the thickness T₃ of conductive layer 410 formed in openings 409 _(I) isin a range from about 10 pm to about 60 μm, and the thickness T₄ ofsolder layer 411 in openings 409 _(I) is in a range from about 20 μm toabout 40 μm. In some embodiments, the thickness T₅ of conductive layer410 formed in openings 409 _(II) is in a range from about 12 μm to about40 μm, and the thickness T₆ of solder layer 411 in openings 409 _(II) isin a range from about 5 μm to about 40 μm.

Afterward the solder layer 407 is deposited and the photoresist layer408 is removed, as shown in FIG. 4E in accordance with some embodiments.The removal process may involve dry or wet etching. After thephotoresist layer 408 is removed, an etch process is performed to removeplating seed layer 404 not covered by the conductive layers 407, 410,and solder layer 411. The conductive layer 407, conductive layer 410,and solder layer 411 in the openings (409 _(I)) are exposed to formexternal connectors (or bump structures) 412. Similarly, the conductivelayer 410 and solder layer 411 in openings (409 _(II)) are also exposedto form connectors (or bump structures) 413. A reflow process is thenperformed to prepare the external connectors 412 and 413 for bonding.FIG. 4E shows the connectors 412 and 413 after the reflow process, inaccordance with some embodiments.

Following the reflow process described above, region 400 is singulatedinto individual piece from the entire substrate 401 and becomes packageddie 110 _(A), which is ready for further packaging. The sigulationprocess is a sawing process, in accordance with some embodiments.

Packaged die 110 _(B) have one-size external connectors, as shown inFIG. 2A. The process sequence for forming external connectors ofpackaged die 110 _(B) can be extracted from the process flows describedin FIGS. 3A-3E and FIGS. 4A-4E.

After interconnect substrates 120′, packaged dies 110 _(A), and packageddies 110 _(B) are prepared or provided, they are assembled on substrates130′. FIGS. 5A-5D illustrate cross-sectional views of a sequential flowof forming die package 100′, in accordance with some embodiments. FIG.5A shows that a substrate 130′ is provided. Substrate 130′ includes anumber of bonding structures 501, which are formed over interconnectstructure 505. In some embodiments, bonding structures 501 are bondingpads. In some embodiments, there is a solder layer over the bonding padson each of the bonding structures 501, which become bump structuresafter subsequent processing. Interconnect structure 505 includesconductive layers, such as metal layers 503, and vias 504, such asplating through holes (PTHs), formed in dielectric material(s) inaccordance with some embodiments. Vias 504 are electrically connected tobonding pads 506 on the other side substrate 130′. Connectors would beformed on bonding pads 506 at a later stage, which will be describedbelow. In some embodiments, substrate 130′ includes dielectricmaterial(s) made of a composite material composed of woven fiberglasscloth with an epoxy resin binder that is flame resistant.

Substrate 130′ also includes an opening 502 to house interconnectsubstrate 120′. FIG. 5B shows the interconnect substrate 120′ beingplaced in opening 502 and being connected to the interconnect structure505 of substrate 130′. FIG. 5B shows that solder balls 125′ are placedin a space between the interconnect structure 505 and substrate 130′.Solder balls 125′ are soldered to neighboring conductive structure ofinterconnect structure 505 and contact structures 311 of interconnectsubstrate 120′ to physically and electrically connect interconnectsubstrate 120′ with substrate 130′, in accordance with some embodiments.

After the interconnect substrate 120′ is bonded to substrate 130′,packaged dies 110 _(A) and 110 _(B) are bonded to interconnect substrate120′ and substrate 130′, as shown in FIG. 5C in accordance with someembodiments. Either packaged die 110 _(A) or packaged die 110 _(B) canby bonded first. In addition, after one packaged die is bonded, anelectrical test can be conducted to ensure the bonding of the packageddie is good before the other packaged die is bonded. For example,packaged die 110 _(A) is picked and placed over substrate 130′ to bebonded to bonding structures 501 to form bonded structures 115 _(A) anda portion of external connectors (or bump structures) 310 ofinterconnect substrate 120′ to form bonded structures 115 _(B). Thebonding process involves solder reflow. Afterwards, an electrical testis conducted to ensure the bonding of packaged die 110 _(A) yields goodresults before packaged die 110 _(B) is bonded to the remainingconnectors 310 of interconnect substrate 120′, in some embodiments. Theelectrical test enables screening of poorly bonded packaged dies toprevent wasting additional resources, such as packaged dies 110 _(B), bybonding to known bad packaged structures.

After the electrical test is done, packaged die 110 _(B) is bonded tothe remaining connectors 310 of interconnect substrate 120′ to formbonded structures 115 _(B), in some embodiments. However, the electricaltest can be optional. In some embodiments, another electrical test isperformed after packaged die 110 _(B) is bonded. This other electricaltest can check the quality of bonding of packaged die 110 _(B) to reducewaste of resources. After both packaged dies 110 _(A) and 110 _(B) arebonded to substrate 130′ and interconnect substrate 120′, a moldingcompound 512 is applied over substrate 130′ to cover packed dies 110_(A) and 110 _(B) and to fill the space underneath packaged dies 110_(A) and 110 _(B), a shown in FIG. 5D in accordance with someembodiments. In some embodiments, an underfill (not shown) is applied tofill the space under packaged dies 110A and 110B before molding compound512 is applied. A thermal reflow process is performed to set the moldingcompound 512. If an underfill is applied, a thermal reflow process isalso performed immediately afterwards to set the underfill.

After the molding compound 512 is formed, external connectors (such assolder balls) 138′ are formed on bonding pads 506 to form die package100′, as shown in FIG. 5D in accordance with some embodiments. Theprocess could involve turning substrate 130′ upside down and placingsubstrate 130′ on a glue layer (not shown) with molding compound 512contacting the glue layer. After substrate 130′ is secured to the gluelayer, solder balls 138′ are placed over bonding pads 506 and are bondedto bonding pads 506 by reflow. Die package 100′ is then singulated to beseparated from other did packages 100′ of substrate 130′. FIG. 5D showsdie package 100′ in accordance with some embodiments.

FIG. 6 shows a cross-sectional view of a die package 100″, in accordancewith some embodiments. Die package 100″ includes a packaged die 110 _(C)and a packaged die 110 _(D). Both packaged die 110 _(C) and packaged die110 _(d) have large numbers of inputs/outputs (I/Os). As a result, theexternal connectors for them are small bumps, such as micro-bumps(μ-bumps). Both packaged dies 110 _(C) and 110 _(D) are bonded to aninterconnect substrate 120″ to form bonding structures 115″. A gluelayer 610 is used to adhere interconnect substrate 120″ to substrate (orpackage substrate) 130″. The interconnect substrate 120″ is electricallyconnected to interconnect structure 135′ of substrate 130′ viaconnecting devices, such as wire bonds 125″. Other types of connectingdevices, such as solder balls 125′ described above may also be used. Anopening similar to opening 502 described above to house interconnectsubstrate 120′ may also be formed to accommodate interconnect substrate120″. FIG. 6 also shows external connectors 138″ bonded to substrate130″.

The formation mechanisms for interconnect substrate 120″ are similar tothose of interconnect substrate 120′. The formation mechanisms forpackaged dies 110 _(C) and 110 _(D) are similar to the formationmechanisms of packaged die 110 _(B) described above. Substrate 130″ issimilar to substrate 130′; however, the interconnect structures andbonding structures on substrate 130″ could be arranged differently fromsubstrate 130′.

After interconnect substrate 120″, packaged die 110 _(C), and packageddie 110 _(D) are prepared or provided, they are assembled on substrate130″. FIGS. 7A-7E illustrate cross-sectional views of a sequential flowof forming die package 100″, in accordance with some embodiments. FIG.7A shows a packaged die 110 _(C) is picked and placed over ainterconnect substrate 120″ to be bonded to substrate 120″. Packaged die110 _(C) is then bonded to interconnect substrate 120″. Electricaltesting (or probing) is then conducted to test the quality of bondingand to test the quality of packaged die 110 _(C) by electrical probes710, as shown in FIG. 7B in accordance with some embodiments. However,the electrical testing is optional.

Afterwards, interconnect substrate 120″ is attached to substrate 130″,such as by a glue layer (not shown), as mentioned above. In addition,electrical connection is made between interconnect substrate 120″ andsubstrate 130″. FIG. 7C shows that the electrical connection is made bywire bonds 125″, in accordance with some embodiments. Following makingthe electrical connection, a packaged die 110 _(D) is placed overinterconnect substrate 120″ to be bonded to it, as shown in FIG. 7D inaccordance with some embodiments.

After packaged die 110 _(D) is bonded to interconnect substrate 120″, amolding compound 712 is formed over substrate 130″ to protect packageddies (110 _(C) and 110 _(D)) and substrate (120″) and connectingstructures (bonding structures between packaged dies and substrate 120″,and wire bonds 125″) over substrate 130″. In some embodiments, anunderfill is first formed under packaged dies 110 _(C) and 110 _(D)prior to forming molding compound 712. However, forming the underfillfirst is optional. Some molding compound materials can also act asunderfill to fill the space between packaged dies 110 _(C)/110 _(D) andsubstrate 120″. After the molding compound 712 is formed, externalconnectors 138″ are formed on the opposite side (opposite from bondedpackaged dies 110 _(C) and 110 _(D)) to form die package 100″, as shownin FIG. 7E. As mentioned above, each substrate 130″ could include anumber of die packages. Die packages 100″ are then singulated intoindividual pieces. FIG. 7E shows die package 100″ after it has beensingulated.

The process flow described above to form die package 100″ is merely oneembodiment. Other process flow may also be used. For example,interconnect substrate 120″ could have been placed on substrate 130″first before packaged dies 110 _(C) and 110 _(D) being bonded tosubstrate 120″. Further, packaged die 110 _(D) could have been bonded tointerconnect substrate 120″ before packaged die 110. Choosing which dieto bond first depends on the components on die package 100″ and howthese components are used. For example, packaged die 110 _(C) may bebonded first because the testing of packaged die 110 _(D) could requirethe presence of package die 110 _(C). Other considerations may be neededin deciding the sequence of bonding and whether to conduct electricaltesting in the sequence of forming die package 100″.

The embodiments described above show two packaged dies bonded in eachdie package, such as packaged dies 110 _(A) and 110 _(B) on die package100′ or packaged dies 110 _(C) and 110 _(D) on die package 100″. Therecould be more than two packaged dies on each die package. FIG. 8 shows atop view of a die package 100* with three packaged dies, 110 _(E), 110_(F), and 110 _(G), bonded an interconnect substrate 120*, which isbonded to a substrate 130*, in accordance with some embodiments.Interconnect substrate 120* is similar to interconnect substrate 120″described above and substrate 130* is similar to substrate 130″described above. The cross-sectional view of die package 100* is similarto the cross-sectional view of die package 100″ of FIG. 6. Higher numberof die packages, such as 4, 5, or more, could be arranged and connectedto the interconnect substrate 120* similar to substrate 120′ or 120″described above and be directly or indirectly connected to a substrate130* similar to substrate 130′ or 130″ described above.

As mentioned above in the description for FIGS. 5C, 7B and 7D, after oneor more packaged dies, such as 110 _(A), 110 _(B), 110 _(C), and/or 110_(D), are bonded to interconnect substrate 120′ or 120″, electricaltests can be conducted to test the quality of the bonding and alsopossibly the functionalities of the bonded packaged die(s). In someembodiments, interconnect substrate 120′ has a number of probing pads910 that are not covered by packaged dies 110 _(A) and 110 _(B), asshown in FIG. 9A in accordance with some embodiments. FIG. 9A shows atop view of FIG. 5C, in accordance with some embodiments. In someembodiments, probing pads 910 are formed by the top metal layer of RDLof redistribution structure 302 (see FIG. 3E). In some otherembodiments, areas of probing pads 910 are opened along with openings306 and probing pads 910 are made of conductive layer 307 or acombination of conductive layer 307 and solder layer 308. Interconnectstructures are formed between probing pads 910 and packaged dies 110_(A) and/or 110 _(B) to enable electrical testing. FIG. 9A shows thatthe probing pads 910 are placed on a surface of interconnect substrate120′ not covered by the packaged dies 110 _(A) and 110 _(B), and areclose to packaged die 110 _(B) (small die). However, probing pads 910can be placed in different places. For example, some probing pads 910can be placed to surround packaged die 110 _(A) to allow shorterconnections to devices in packaged die 110 _(A), as shown in FIG. 9B inaccordance with some embodiments.

Probing pads 910 can be used to test the quality and connectivity of thebonding structures formed between packaged dies 110 _(A), 110 _(B), andinterconnect substrate 120′. To test connectivity between signalstructures and power-source structures or between signal structures andground structures, metal lines are needed to connect these structures.However, the electrical connections used for testing need to bedisconnected after testing is completed to allow the devices in thepackaged dies 110 _(A) and 110 _(B) to work. FIG. 10A shows electricalconnections between probing pads 910 _(A), 910 _(B), 910 _(C), 910 _(D)and bonding structures 115 _(B) of packaged dies 110 _(B) and/or 110_(A), in accordance with some embodiments. Probing pads 910 _(A) and 910_(C) connect bonding structures 115 _(B) that are connected to “Signal1”, “Ground 1”, “Ground 2”, and “Signal 3” structures via metal lines920. Metal lines 920 are RDLs of redistribution structure 302 describedabove. The metal lines 920 contact bonding structures 115 throughexternal connectors (or bump structures) 310 of interconnect substrate120″.

By placing electrical-test probers with probing pads 910 _(A) and 910_(C) and supplying current and/or voltage between probing pads 910 _(A)and 910 _(C) various electrical tests can be performed. For example, totest the quality of bonding, a current can be applied between probingpads 910 _(A) and 910 _(C). The voltages of probing pads 910 _(A) and910 _(C) are then measured to calculate the resistance between probingpads 910 _(A) and 910 _(C). The value of the resistance measured wouldreflect the quality of bonding. A value higher than an expected rangecould indicate improper bonding, such as cracking, mis-alignment, etc.The structures connected between probing pads 910 _(A) and 910 _(C)enable testing the connection to the grounding and signal structures.

Similarly, probing pads 910 _(B) and 910 _(C) connect bonding structures115 _(B) that are connected to “Signal 2”, “Power 1”, “Power 2”, and“Signal 4” structures through electrical lines 925 (lines with circles).By placing electrical-test probers with probing pads 910 _(B) and 910_(D) and supplying current and/or voltage between probing pads 910 _(B)and 910 _(D) various electrical tests can be performed. For example, totest the quality of bonding, a current can be applied between probingpads 910 _(B) and 910 _(D). The voltages of probing pads 910 _(B) and910 _(D) are then measured to calculate the resistance between probingpads 910 _(B) and 910 _(D). The value of the resistance measured wouldreflect the quality of bonding. A value higher than an expected rangecould indicate improper bonding, such as cracking, mis-alignment, etc.The structures connected between probing pads 910 _(B) and 910 _(D)enable testing the connection to the power and signal structures.

FIG. 10A shows that metal line 920 _(A) of metal lines 920 cross metallines 925 _(A), 925 _(B), 925 _(C), 925 _(D) of metal lines 925 from atop view. To avoid these lines crossing each other, they can be placedat different RDL level. For example, metal line 920 _(A) could be placedat an RDL level, which is below or above the RDL for metal lines 925_(A), 925 _(B), 925 _(C), 925 _(D). Similarly, metal line 925 _(A) crossa few metal lines for connecting probing pads 910A and 910C from a topview. Metal line 925 _(A) may be place at different RDL level from themetal lines it might cross if they are placed on the same RDL level.

Metal lines 920 could be on the same RDL level or different RDL levels.Similarly, metal lines 920 could be on the same RDL level or differentRDL levels. As described above, multiple levels of RDLs could be used toavoid metal line crossing.

The structures in FIG. 10A described are called daisy-chain structures.They are useful in testing quality of bonding between packaged dies andsubstrate. The structures described are merely examples, there could beother types of daisy-chain structures. After the testing is completed,the metal lines, such as metal lines 920 and 925, between metal pads 910_(A), 910 _(B), 910 _(C), 910 _(D), and bonding structures 115 _(B) needto be severed (or cut) to allowed devices in packaged dies 110 _(A) and110 _(B) to function properly. FIG. 10B shows severed metal lines 920,925 between metal pads 910 _(A), 910 _(B), 910 _(C), 910 _(D), andbonding structures 115 _(B), in accordance with some embodiments. Insome embodiments, metal lines 920, 925 are severed by laser. Portions ofmetal lines 920, 925 are exposed to enable severing by a severing tool,such as laser. Laser melts metal lines 920, 925 and separates them intodiscontinued pieces.

FIGS. 11A-11C show cross-sectional views of a sequential flow of testingand bonding packaged dies to form die package 100′, in accordance withsome embodiments. FIGS. 11A-11C illustrate additional details of processand structures described above of FIG. 5C, in accordance with someembodiments. FIG. 11A shows that after packaged die 110 _(A) is bondedto interconnect substrate 120′ and substrate 130′, an electrical testcan be conducted to ensure the bonding of the packaged die 110 _(A) isgood before the other packaged die is bonded. FIG. 11A shows thatprobers 1110 are lowered to contact probe pads 910 described above.Probing pads 910 are on the top metal layer to allow contact withprobers 1110. However, this operation is optional.

Afterwards, packaged die 110 _(B) is bonded to interconnect substrate120′. Probers 1120 are then lowered to contact probe pads 910 to makeelectrical tests, as shown in FIG. 11B in accordance with someembodiments. The probe pads 910 contacted by probers 1120 could be thesame or different from the probe pads contacted by probers 1110. Some ofthe electrical tests involve daisy-chain structures with probe pads 910connected to bonding structures 115B and metal lines 920, 925 describedabove. After the test is completed, the interconnecting metal lines,such as 920, 925, are severed (or cut, or separated), as shown in FIG.11C. In some embodiments, the interconnecting metal lines (such as 920,925) are cut by laser, which is produced by a severing tool 1130.Following the severance, molding compound 512 and external connectors138′ are formed, as described in FIG. 5D in accordance with someembodiments.

Traditionally, the quality of bonding of packaged dies can be testedafter the die package is completed. The test structures and the probingstructures on interconnect substrate described above enable testingwithout waiting until the die package is completed assembled. Ifelectrical data reveal that packaged dies or bonding structures are lessthan perfect, they can be removed and be replaced by new packaged dieswith newly formed bonding structures. However, such rework is notpossible for finished die package, when the molding compound is formed.The mechanisms for forming test structures with probing pads andsevering connecting metal lines after testing could reduce manufacturingcost.

Embodiments of mechanisms for testing a die package with multiplepackaged dies on a package substrate use an interconnect substrate toprovide electrical connections between dies and the package substrateand to provide probing structures (or pads). Testing structures,including daisy-chain structures, with metal lines to connect bondingstructures connected to signals, power source, and/or groundingstructures are connected to probing structures on the interconnectsubstrate. The testing structures enable determining the quality ofbonding and/or functionalities of packaged dies bonded. After electricaltesting is completed, the metal lines connecting the probing structuresand the bonding structures are severed to allow proper function ofdevices in the die package. The mechanisms for forming test structureswith probing pads on interconnect substrate and severing connectingmetal lines after testing could reduce manufacturing cost.

In some embodiments, a semiconductor die package is provided. Thesemiconductor die package includes a first packaged die, and aninterconnect substrate with a redistribution structure. The firstpackaged die is bonded to the redistribution structure, and theinterconnect substrate includes a plurality of probing pads whoseelectrical connections to the first packaged die being severed. Thesemiconductor die package also includes a package substrate with aninterconnect structure. The interconnect substrate is bonded to thepackage substrate, and wherein the package substrate is electricallyconnected to the first packaged die.

In some other embodiments, a method of forming a semiconductor diepackage is provided. The method includes bonding an interconnectsubstrate to a package substrate, and bonding a first packaged die tothe package substrate and to the interconnect substrate. The method alsoincludes bonding a second packaged die to the interconnect substrate,and performing an electrical test on a plurality of test structures. Theplurality of test structures include a plurality of probing padselectrically connected to devices in the first packaged die and thesecond packaged die by metal lines. The method further includes severingthe metal lines to terminate electrical connection between the pluralityof probing pads, the first packaged die, and the second packaged die.

In yet some other embodiments, a method of forming a semiconductor diepackage is provided. The method includes bonding an interconnectsubstrate to a package substrate, and bonding a first packaged die tothe package substrate and to the interconnect substrate. The method alsoincludes bonding a second packaged die to the interconnect substrate,and performing an electrical test on a plurality of test structures. Theplurality of test structures include a plurality of probing padselectrically connected to devices in the first packaged die and thesecond packaged die by metal lines. The method further includes severingthe metal lines to terminate electrical connection between the pluralityof probing pads, the first packaged die, and the second packaged die. Inaddition, the method includes forming a molding compound over thepackaged substrate to cover the first packaged die and the secondpackaged die bonded to the package substrate and the interconnectsubstrate. Additionally, the method includes forming external connectorsof the package substrate.

In an embodiment, a semiconductor die package is provided. The packageincludes a first packaged die bonded to an interconnect substrate by afirst plurality of bonding structures and a second packaged die bondedto the interconnect substrate by a second plurality of bondingstructures. The package further includes a plurality of test structures,wherein the plurality of test structures comprises a plurality ofprobing pads, a first test structure of the plurality of test structuresbeing electrically isolated from the first plurality of bondingstructures, the second plurality of bonding structures, and other onesof the plurality of probing pads.

In yet another embodiment a semiconductor die package is provided. Thepackage includes a first packaged die bonded to an interconnectsubstrate by a first plurality of bonding structures and a secondpackaged die bonded to the interconnect substrate by a second pluralityof bonding structures. The package further includes a test structure,wherein the test structure comprises a probing pad, a first line sectionand a second line section, the first line section having a first end anda second end, the first end terminating at the probing pad, the secondline section having a third end and a fourth end, the third endterminating at one of the first plurality of bonding structures or oneof the second plurality of bonding structures, the fourth end and thesecond end being disconnected and aligned. A molding compound is formedover the first packaged die, the second packaged die, and theinterconnect substrate.

In yet still another embodiment a semiconductor die package is provided.The package includes a first substrate bonded to an interconnectsubstrate by a first plurality of bonding structures and a secondsubstrate bonded to the interconnect substrate by a second plurality ofbonding structures. The package further includes a plurality of teststructures on the interconnect substrate, wherein each of the pluralityof test structures comprise a probing pad connected to a discontinuousconductive line, a first segment of the discontinuous conductive linecoupled to a corresponding one of the first plurality of bondingstructures or a corresponding one of the second plurality of bondingstructures, a second segment of the discontinuous conductive linecoupled to the probing pad, terminating ends of the first segment andthe second segment being separated by a gap. A molding compound isformed over the first substrate, the second substrate, and theinterconnect substrate.

Although embodiments of the present disclosure and their advantages havebeen described in detail, it should be understood that various changes,substitutions and alterations can be made herein without departing fromthe spirit and scope of the disclosure as defined by the appendedclaims. For example, it will be readily understood by those skilled inthe art that many of the features, functions, processes, and materialsdescribed herein may be varied while remaining within the scope of thepresent disclosure. Moreover, the scope of the present application isnot intended to be limited to the particular embodiments of the process,machine, manufacture, composition of matter, means, methods and stepsdescribed in the specification. As one of ordinary skill in the art willreadily appreciate from the disclosure of the present disclosure,processes, machines, manufacture, compositions of matter, means,methods, or steps, presently existing or later to be developed, thatperform substantially the same function or achieve substantially thesame result as the corresponding embodiments described herein may beutilized according to the present disclosure. Accordingly, the appendedclaims are intended to include within their scope such processes,machines, manufacture, compositions of matter, means, methods, or steps.

What is claimed is:
 1. A semiconductor die package, comprising: a firstpackaged die bonded to an interconnect substrate by a first plurality ofbonding structures; a second packaged die bonded to the interconnectsubstrate by a second plurality of bonding structures; and a pluralityof test structures, wherein the plurality of test structures comprises aplurality of probing pads, a first test structure of the plurality oftest structures being electrically isolated from the first plurality ofbonding structures, the second plurality of bonding structures, andother ones of the plurality of probing pads.
 2. The semiconductor diepackage of claim 1, wherein the plurality of probing pads is severedfrom the first plurality of bonding structures and the second pluralityof bonding structures by a laser tool.
 3. The semiconductor die packageof claim 1, wherein at least some of the plurality of probing pads arecovered by the second packaged die.
 4. The semiconductor die package ofclaim 1, further comprising: a molding compound over the first packageddie, the second packaged die, and the interconnect substrate; andexternal connectors of the interconnect substrate extending beyond thefirst packaged die and the second packaged die.
 5. The semiconductor diepackage of claim 1, further comprising a third plurality of bondingstructures bonding the first packaged die to another substrate.
 6. Thesemiconductor die package of claim 1, wherein devices in the firstpackaged die and the second package die include signal structures,power-source structures, grounding structures, and combinations thereof.7. The semiconductor die package of claim 1, wherein the first packageddie comprises a processor and the second packaged die comprises amemory.
 8. A semiconductor die package, comprising: a first packaged diebonded to an interconnect substrate by a first plurality of bondingstructures; a second packaged die bonded to the interconnect substrateby a second plurality of bonding structures; a test structure, whereinthe test structure comprises a probing pad, a first line section and asecond line section, the first line section having a first end and asecond end, the first end terminating at the probing pad, the secondline section having a third end and a fourth end, the third endterminating at one of the first plurality of bonding structures or oneof the second plurality of bonding structures, the fourth end and thesecond end being disconnected and aligned; and a molding compound overthe first packaged die, the second packaged die, and the interconnectsubstrate.
 9. The semiconductor die package of claim 8, furthercomprising a package substrate, wherein the first packaged die and thesecond packaged die are bonded to a first side of the interconnectsubstrate, and wherein a second side of the interconnect substrate isbonded to the package substrate, the second side of the interconnectsubstrate not being electrically bonded to the package substrate. 10.The semiconductor die package of claim 9, wherein the interconnectsubstrate is wire bonded to the package substrate.
 11. The semiconductordie package of claim 9, wherein the interconnect substrate is mounted inan opening in the package substrate.
 12. The semiconductor die packageof claim 8, further comprising a package substrate, wherein the firstpackaged die is bonded directly to the package substrate by a thirdplurality of bonding structures.
 13. The semiconductor die package ofclaim 8, further comprising solder joints extending along sidewalls ofthe interconnect substrate.
 14. The semiconductor die package of claim8, wherein the first packaged die comprises a processor.
 15. Thesemiconductor die package of claim 8, wherein the second packaged diecomprises a memory.
 16. A semiconductor die package, comprising: a firstsubstrate bonded to an interconnect substrate by a first plurality ofbonding structures; a second substrate bonded to the interconnectsubstrate by a second plurality of bonding structures; and a pluralityof test structures on the interconnect substrate, wherein each of theplurality of test structures comprise a probing pad connected to adiscontinuous conductive line, a first segment of the discontinuousconductive line coupled to a corresponding one of the first plurality ofbonding structures or a corresponding one of the second plurality ofbonding structures, a second segment of the discontinuous conductiveline coupled to the probing pad, terminating ends of the first segmentand the second segment being separated by a gap; and a molding compoundover the first substrate, the second substrate, and the interconnectsubstrate.
 17. The semiconductor die package of claim 16, wherein thefirst substrate and the second substrate are bonded to a first side ofthe interconnect substrate.
 18. The semiconductor die package of claim16, further comprising a package substrate wire bonded to a first sideof the interconnect substrate, wherein the molding compound covers thewire bonding.
 19. The semiconductor die package of claim 16, wherein theinterconnect substrate is bonded to a recess of a package substrate. 20.The semiconductor die package of claim 16, wherein the interconnectsubstrate is bonded to a package substrate using an adhesive.